To meet an Internet access requirement of passengers in a vehicle in rail transport, a vehicle-ground communications system may be deployed for the vehicle. The vehicle-ground communications system may be deployed using a WLAN technology. A radio link is set up between a vehicle-mounted access point (AP) on the vehicle and a trackside AP deployed along a track. A device of a passenger in the vehicle accesses a network using the vehicle-mounted AP and the trackside AP. During running of the vehicle, the vehicle-mounted AP is handed over between multiple trackside APs. Because the vehicle runs at a high speed, to shorten a time for handing over the vehicle-mounted AP between the trackside APs, one channel is configured for all the trackside APs, and the channel is also configured for vehicle-mounted APs on all vehicles. Because vehicle-mounted APs on one vehicle and a next vehicle use the same channel, interference between the vehicle-mounted APs on the two vehicles is serious.